【Abstract】 Objective To investigate the influencing factors of venous thrombosis after venous puncture (CVC)/peripheral venous puncture (PICC) in patients with cancer. Methods The hospitalized chemotherapy patients underwent CVC/PICC catheterization from January 2016 to January 2018 in our hospital were retrospectively analyzed for age, sex, tumor type (blood system tumor and nonhematologic tumor), and number of chemotherapy. The prothrombin time (PT), catheterization time, followup time and followup, activity frequency and intensity were associated with venous thrombosis. Results 234 patients met the inclusion criteria were enrolled, and 63 of them developed venous thrombosis (incidence rate 26.92%). There was no significant correlation between age, gender and thrombosis rate (P＞0.05). Univariate analysis showed that tumor type, prothrombin time (PT), number of chemotherapy, catheterization time, followup mode and activity were correlated with venous thrombosis (P＜0.05). Multivariate analysis indicated that catheterization time and followup were independent risk factors for thrombosis after venous catheterization (P＜0.05). The catheterization time was greater than 14 days, which significantly increased the incidence of venous thrombosis. The rate of venous thrombosis in patients with regular outpatient followup was lower than that of telephone and other followup, and outpatient followup was more likely to be detected early in thrombosis. Conclusion Tumor type, PT, number of chemotherapy, catheterization time, followup mode and time, activity frequency and intensity of venous catheterization are associated with venous thrombosis. The daily care of medical staff should identify the high risk factors of thrombosis, strengthen the mission of patients, and follow up on time and out of the catheter in time to reduce the incidence of venous thrombosis after CVC/PICC catheterization.